BHO (Butane Hash Oil)

BHO (Butane Hash Oil) is a cannabis concentrate produced by passing liquefied light hydrocarbon — n-butane, isobutane, propane, or blends — through cannabis material in a closed-loop extraction system to dissolve cannabinoids and terpenes. The solvent is then recovered and reused, and residual gas is purged under vacuum. BHO is the umbrella for shatter, wax, budder, crumble, sugar, sauce, diamonds, live resin, HCFSE, and HTFSE.

Process parameters are well defined. The closed-loop system is a sealed circuit of solvent tank, extraction column, collection vessel, recovery pump, chiller, and vacuum pump. Columns are chilled to -20°F to -40°F using dry-ice jackets or glycol chillers. Extraction pressure runs approximately 150 PSI typical, 200 PSI maximum. Purge is accomplished in a vacuum oven at 80–115°F (27–46°C) for 24–72 hours. Winterization and dewaxing are performed by dissolving the crude in ethanol at -20°C to -80°C and filtering, by inline jacketed dewaxing columns, or by color-remediation columns (CRC) packed with activated clay and silica.

Propane (bp -43.6°F) runs at higher pressures and lower temperatures, preserves terpenes better, and purges faster; butane (bp 30.2°F) enables a wider texture variety; blends balance yield, terpene retention, and workability. Yield runs 15–25% of dried flower biomass, with refined potency of 60–90%+ THC. The technical lineage begins with D. Gold's 1971/1973 Cannabis Alchemy, continues through Erowid's 1991 "Hash Honey Oil Technique" (open-blasting), and matures with BudderKing's commercialized butane budder around 2003–2005, closed-loop systems through the 2010s, and modern automated units processing up to 18 lb dry or 25 lb fresh-frozen biomass per hour. Synonyms include PHO (propane hash oil), hash oil, honey oil, dabs, and hydrocarbon extract.

⚠️ Regulatory burden is substantial. C1D1 (Class I, Division 1) rooms are required because hydrocarbon vapors are present under normal operation: blast-rated walls (5–7 PSI), 6–12 air changes per hour under negative-pressure HVAC, LEL (lower explosive limit) gas detection with auto-shutoff, Group D explosion-proof electrical, and fire suppression. Residual butane limits include Colorado 5,000 ppm (post-2017), California 1,000 ppm inhaled and 5,000 ppm other. Applicable standards include NFPA 58, NFPA 30, OSHA 29 CFR 1910.119, IFC Chapter 39, and ASTM D37.04 work item WK60435. → See also: Live resin, Shatter, Wax, Budder, Sauce, Diamonds, Extract